Node js Port 3000 already in use but it actually isn t

Question

I have been working with a node js project for a few weeks and it has been working great  Usually  I use npm start to run my app and view it in a browser on localhost  port 3000   Today  I started to get the following error while using npm start   Server started on port 3000                                                                                                                                                                                          Port 3000 is already in use    I have checked the resource monitor and I have no other process running on port 3000  Why would I be getting this error message   In my app js I have the following code to set the port   is this incorrect  It worked fine before so I m not sure what I am doing wrong      Set Port app set  port    process env PORT    3000    app listen app get  port    function         console log  Server started on port   app get  port           Thanks for the help      EDIT   I have tried running netstat and TCPView to check what process is using the port  but there is nothing using that port  I also tried restarting my laptop but I still get the same error

User · Answer

In ubuntu first grab the process by using port number: sudo lsof -i:3000 then use kill command to kill the process, for example if the process PID is 4493 the use command: kill 4493 , for mac or windows find the related command

User · Answer

This started happening to me today on Windows  I have restarted my computer and checked that nothing is on the port 3000 and it isn t  I tried using 3001  3005 with the same result  In the end I moved to 8881 and it works now  The only thing that changed for me was installing windows updates and updating source-map-explorer  As this also occurs in other apps its either something with Web Storm or windows  My guess is the ports may be locked down but the ones in the 88XX range are not

User · Answer

if you are using webstorm just make sure your default port is not 3000 from  file -  settings -  Build  Execution  Deployment -  Debugger And there change     Built-in server port   and set it to  63342  or see this answer  Change WebStorm LiveEdit Port  63342

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I have solved this problem because the MongoDB or there is another app u had run it before on this port  so to solve it kill the process from task manager  or just change the number of the port from 3000 to any other one

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I was using express server with nodemon on NodeJS  I got the following message and it seems an error     node   bin www Port 3000 is already in use   There is a general solution that if you terminate all node server connections  you can add this code in your package json file    scripts          start    node   bin www        stop    taskkill -f -im node exe       In addition  I ve found several solutions windows command and bash on Win 10 x64   All my notes are here       Terminate all NodeJS Server Connections    taskkill -f -im node exe SUCCESS  The process  node exe  with PID 14380 has been terminated  SUCCESS  The process  node exe  with PID 18364 has been terminated  SUCCESS  The process  node exe  with PID 18656 has been terminated        Example  Open the Windows Task Manager and see  node exe  PID number on Windows   gt  gt  Command Line   netstat      netstat -a -n -o   netstat -ano       Kill a process in Windows by Port Number  Example   For Help     taskkill      tskill      Code 1     taskkill -pid 14228 ERROR  The process with PID 14228 could not be terminated  Reason  This process can only be terminated forcefully  with  F option     Code 2     taskkill -f -pid 14228 SUCCESS  The process with PID 14228 has been terminated    Code 3     tskill 14228       Command line for looking at specific port  in cmd     netstat -ano   find  14228    in bash     netstat -ano   grep  14228  or   netstat -ano   grep 14228       Find node exe using  tasklist  command  in cmd     tasklist   find  node    in bash     tasklist   grep node   tasklist   grep node exe node exe                     14228 Console                    2     48 156 K node exe                     15236 Console                    2     24 776 K node exe                     19364 Console                    2     24 428 K

User · Answer

Simple in linux   Open your terminal Free port from processes -  kill   lsof -t -i  port

User · Answer

It s very simple  You can fix it in 2 easy steps   Check your environment variables if there is a key entry with name  quot PORT quot   If found delete that entry or rename it to something else   It turns out that some other program is using that variable  Usually when you start react-scripts it will look for an environment variable with that title PORT

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I also encountered the same issue  The best way to resolve is  for windows    Go to the Task Manager   Scroll and find a task process named  Node js  Server-side JavaScript   End this particular task    There you go  Now do npm start and it will work as before

User · Answer

In my circumstance I had just started using VS Code and had followed a tutorial using Sequelize   In the end I had a bin www file that had the listen   in there  I didn t know about this and I was running my app by running node app js  when it didn t work I then added in the express server stuff with  listen    which worked fine     But when starting to use nodemon and VSCode it was pointed at bin www and that required my app js    Long story short I had added  listen   to my app js and was running app js directly when I should have not added that and run bin www

User · Answer

This happens to me sometimes  EADDR in use   Typically there is a terminal window hiding out in the background that is still running the app  You can stop process with ctrl C in the terminal window     Or  perhaps you are listening to the port multiple times due to copy pasta

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You can search on how to kill that process   For Linux Mac OS search  sudo  run this in the terminal     lsof -i tcp 3000   kill -9 PID   On Windows   netstat -ano   findstr  3000 tskill typeyourPIDhere    change tskill for taskkill in git bash

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Came from Google here with a solution for High Sierra   Something changed in the networking setup of macos and some apps  including ping  cannot resolve localhost   Editing  etc hosts seems like a fix   cmd  sudo nano  etc hosts  content 127 0 0 1 localhost  Or simply  if you re sure your  etc hosts is empty  sudo echo  127 0 0 1 localhost   gt   etc hosts

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For windows user  Just simple stop all processes of Node js in Task   Manager   Hope it will help

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server or app listen   methods might be added at 2 places  Search for listen   methods in the for the application startups thats why its returning as Server started at Port XXXX and Port XXXX already in use message coming side by side

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Sometimes it happens  as  sova proposed This happens to me sometimes  EADDR in use  Typically there is a terminal window hiding out in the background that is still running the app  And that s also right with me   It happens  when you have opened terminal for long time  yeah you have right  you have stop the process  But sometimes it didn t stop in the background  So best solution is that you close the terminal and start it again  It will solves your problem  becuase in my case it works   Also    sudo lsof -i  lt PORT NO gt    close the instance for present time but unable to stop the process in background  So for one time    sudo kill  lt PID gt    works  but again when we update our code and save  this problem occurs again as with Nodemon   So exit the terminal will solve the problem  OR     killall -9 node

User · Answer

Killing a process that owns port 3000  First  let   s take a look at how we can kill a process that has a port open   Using the lsof command  we can retrieve the PID that has the given port     lsof -i  3000 -t 12345   Then we can kill this process just by doing     kill 12345   Let   s turn this into a one-liner   lsof -i 3000 -t   xargs kill   If you   re using an environment variable to set the server port  we can specify that instead of hardcoding our values   lsof -i   PORT  -t   xargs kill   Lastly  we can default to port 3000 if the environment variable isn   t set   lsof -i   PORT -3000  -t   xargs kill   Getting nodemon to execute hooks  Nodemon lets you set up event hooks through nodemon json configuration file        events          crash    sh -c  lsof -i    PORT -3000  -t   xargs kill           This will cause nodemon to execute sh -c  lsof -i    PORT -3000  -t   xargs kill command whenever your app crashes  thereby killing the child process it spawned that   s keeping the port open   or you can try this one  fuser -k PORT-NO tcp   eg   fuser -k 3000 tcp

User · Answer

I got this problem using Git Bash on Windows  I run npm start  or node app js  After terminating it with Ctrl C shortly and trying to start the server again using npm start or node app js then I get this error message   When I do this with the regular Windows Command Prompt  however  it works fine   Or You can do it in another way  Open the Task Manager and Find the  Node js Server-side JavaScript  row  Select that and end task  It should work now   Thanks

User · Answer

check for any process running on the same port by entering the command   sudo ps -ef   You can find the process running on the respective node port  then kill the node by   kill -9  lt node id gt    If the problem still remains then just kill all the node  killall node

User · Answer

I ve seen the same thing and tried all the suggestions above without success  Here are steps that resolve it for me  - turn off wifi - npm start      this should work  - turn on wifi  I m not exactly sure what the root issue is but that resolved it for me

User · Answer

I had the same problem   The below steps work fine on Windows 10     Open Task manager  press Ctrl Alt Delete  Select the  Processes tab  Search for  Node js  Server-side JavaScript  Select it and click on  End task  button   Now you can run npm start   Hope it helps you

User · Answer

For windows users  you can use CurrPorts tool to kill ports under usage easily

User · Answer

Before running nodemon  Please start mongod first  You will never get this error

User · Answer

For windows   The Task Manager would definitely show a node process running  Try to kill the process  it will solve the problem

User · Answer

It may be an admin process running in the background and netstat doesn t show this  Use tasklist   grep node to find the PID of this admin process and then kill PID

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Kills all the running ports  mac    killall node

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If you want to close only one port  just run this command   kill -9   lsof -t -i 3000   The difference between pkill and kill is someone process clay  In kill you apply a filter  you just stop the port you want   The pkill command closes all node processes  pkill -9 node  Use pkill to avoid memory leaks that occur occasionally during development  if there is more than one node  it kills them all   The use of scripts in package json is also exemplified    scripts          server start    cd server  amp  amp  yarn start        server restart    cd server  amp  amp  yarn restart        frontend start    cd frontend  amp  amp  yarn start        frontend restart    kill -9   lsof -t -i 4200   amp  amp  yarn start frontend        scripts          start    nodemon --watch  src      ts  --ignore  src      spec ts  --exec  ts-node  src index ts        restart    pkill -9 node  amp  amp  start        kill    pkill -9 node

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You can use kill-port  In firstly  kill exist port and in secondly create server and listen  const kill   require  kill-port    kill port   tcp        then  d    gt                       Create HTTP server                  server   http createServer app            server listen port       gt                console log  api running on port   port                             catch  e    gt            console error e

User · Answer

Open Task Manager  press Ctrl Alt Del Select the  Processes Tab  Search for  Node js  Server-side JavaScript  Select it and click on  End task  button

User · Answer

I have spent 2h on finding out why EADDRINUSE wasn t allowing me to sart an app  other node-express servers were ok     it started working after adding       lazyConnect  true   to datasource configuration    Don t ask me why it helped  I do not know  I am putting this info here just for people having the same issue

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Maybe you can take this as reference  This single command line can kill the process running on given port   npx kill-port 3000       To kill multiple ports   npx kill-port 3000 8080 4200

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In package json scripts inlcude    start    nodemon app js --delay 1500ms    I believe the issue was for me the time that the old port was not shutting down in time by nodemon for the restart  I experienced the issue using multer

User · Answer

Try opening the localhost in your browser  Just type  localhost 3000 in the address bar  If the app opens-up  it means your previous npm run is still active  Now  you can just make changes to the code and see the effects if you are designing the same app  or if you wanna run another app  just tweak the code  in index js of previously running app  a little-bit and  probably refresh the browser tab  to make it crash         Now go run npm run start again from your new app directory  Hope this helps      or  You can open the Task Manager  WINDOWS KEY X   Task Manager  and you ll see the  Node js Server-side JavaScript  row  Select that and end task    It should work now    If not  change the  env file of your app to include port 3002 and run the new app  This will allow you to run two separate apps on different ports  Cheers

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